Location: indoor or outdoor
Materials: ball or balloon, string, and netting (optional)
Did you ever play tether ball as a kid? It's the game where a volleyball is attached to a pole by a long string. It's a 2-person game where the objective is to hit the ball past your opponent so that the string winds around the pole. If that doesn't make sense, here's a video of it.
What you might not have realized about tether ball when playing it at summer camp is that it is a great game for practicing hand-eye coordination. The great news is that you don't need a real tether ball court to give your kids the opportunity to play. Create your own by inflating a balloon, tying a string to the end of the balloon, and then tying the other end of the string to a secure spot (a railing or a tree branch, for example). You could also just decide to hold the string yourself, if you don't have a good spot to attach it.
Invite your kids to take a turn using their hand to hit the balloon.
Possible Extensions: